Bénédicte Lebeau

A mesoporous silica functionalized by a covalently bound calixarene-based fluoroionophore for selective optical sensing of mercury(II) in water

With the aim of optical sensing of Hg2+ in water, a calixarene bearing two dansyl fluorophores was grafted on a large pore mesoporous silica material (SBA-15) n via two long alkyl chains containing triethoxysilane groups. The characterization of the obtained material 2-SBA-15 shows that the organized structure is preserved after the post-grafting procedure. A detailed study of the complexing and fluorescence properties of 2-SBA-15 is reported. The functionalized material is able to reversibly detect Hg2+ with a response time of a few seconds and a detection limit of 3.3 × 10−7 mol L−1 in water. Furthermore, this system offers a high selectivity over several interfering cations (Na+, K+, Ca2+, Cu2+, Cd2+, Pb2+).

Organically-modified mesoporous silica spheres with MCM-41 architecture

New hybrid inorganic–organic materials displaying both an ordered mesoporous structure and spherical morphology have been synthesised by co-condensation of tetraethoxysilane and organoalkoxysilanes in water–ethanol solution containing ammonia in the presence of surfactant as templating agent.

Synthesis and characterization of mesoporous silicas functionalized by thiol groups, and application as sorbents for mercury (II)

Heavy metal ion (Hg II ) adsorbents with uniform mesopore channels were prepared by functionalizing SBA-15 and SBA-16 type ordered mesoporous silica samples with mercaptopropyl groups according to two routes: post synthesis grafting of pure mesoporous silica and direct functionalization by a co-condensation procedure. XRD, N 2 adsorption-desorption measurements and 29 Si solid state NMR spectroscopy were used to characterize the physico-chemical properties of the organic-inorganic hybrid materials and to investigate the different functionalization processes on the two types of ordered mesoporous silica SBA-15 and SBA-16 materials. Higher contents in organo-functional groups were achieved when following the one-step co-condensation route in comparison with the post-synthesis grafting. However, the evaluation of the diffusion rates of Hg II species in the mesoporous solids by means of an electrochemical method showed faster binding rates for the post-synthesis grafted samples.